This is a set of optional Kyosho 1° Aluminum Rear Hub Carriers, and are intended for use with the Kyosho RB5, ZX-5FS, RT5 and Ultima SC 1/10 vehicles. These aluminum hubs feature 1° rear toe in, as well as large 5x13x4mm outer axle bearings, instead of the standard 5x10x4mm bearing. They also feature 4 upper camber link locations, allowing more rear roll center tuning options. The rear hub carriers attach to the rear lower suspension arms, and hold the bearings that support the rear axles.